Study of coupling angle, variability and coordination of the trunk and lower limb of woment with and without patellofemoral pain during stair ascent and descent before and after pain exacerbation.

Abstract

Patellofemoral pain (PFP) frequently affects the female population causing diffuse anterior or retropatellar pain exacerbated by functional activities, such as going up and down stairs. PFP has as its main characteristic the multifactorial cause resulting from kinematic changes in the proximal, local and distal regions of the knee. Because of the multifactorial context of this disorder, several factors in different joints may be interacting with each other and influencing their development, making it difficult to determine exactly how these interactions occur and how they may lead to the subsequent development of PFP. In addition, these interactions have a great influence on the coordination and variability of the movement performed by these individuals. The main line of study undertaken to understand DFP is biomechanical studies. However, the use of traditional biomechanical analyzes (eg, biomechanical analyzes of specific lower limb joint behavior), as in most studies in this area, provides important but limited information, not exploring how movement is coordinated and interacts between two or more body segments. An analysis that stands out by presenting this characteristic is the approach of dynamic systems. The analysis of dynamic systems is characterized by investigating the interaction between body segments / joints and their contribution to a movement / injury mechanism, rather than investigating the behavior of the parts separately, which is usually done by traditional biomechanical analysis. Given the potential contribution of this analysis to the understanding of PFP, the overall objective of this project is to investigate whether women with PFP exhibit changes in the coupling angles, variability and coordination of the lower limb and trunk compared to asymptomatic women and whether these changes are related with pain and patellofemoral stress. We will select women with and without PFP, who will be oriented to go up and down a 7-step staircase inserted in an experimental set up consisting of nine infrared cameras for kinematic capture of the trunk, hip, knee and foot. Firstly, the individual will arrive at the laboratory and perform 5 stair climbs and descents. On another day, participants will return to the laboratory and undergo an overload protocol prior to data collection in order to exacerbate pain in individuals with PFP. This protocol consists of 15 ascents and descents using a backpack with a load equivalent to 35% of the body mass of each participant.